Terminal bank.



To all whom it may concern oHAnLns r. BALDWIN, or ivronrcnara, new JERSEY, essieuon, BY MESNE ASSIGN- iunurs, T WESTERN anaemic coicrAuY, ruocaronaran, A coaronezrron or sameness sank.

, Be it known that 1, CHARLES F. BALDWIN, a citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Terminal;

Banks, of which the. following is a full,

, clear, concise, and exact description.

This invention relates to terminal banks particularly adapted for use in buildingup contact banks for automatic telephone exchange switchboards, although obviously suita le for many other uses. Its principal object is to provide an improved bank of the above type, wherein the terminals are uniformly and properly spaced and the tendency to sag,iseparate and warp is prao tically nil. To this end a structure is formed of superposed metal terminal strips and 1n-,

sulating compound coated paper, the paper without compound being of" a thickness greater than the distance between adjacent terminal strips of the finished product;

- pressure then serving to effect a uniform spacing, expel all superfluous compoundand compress the paper until its thickness, plus whatever compound remains between layers of paper and metal, equals the required distance between adjacent terminal strips. v The above and other objects of this invention will be fully set forth in the following descriptionand claims, and will be more readily understood by reference to the accompanying drawing, in which- Figure 1 is an enlarged view of a section of the coated paper; Fig. 2 is an elevation of a section of a terminal bank before the application of pressure; Fig. 3 illustrates the condition of the structure of Fig. 2 after compression; Fig. 4 shows the relative thick ness of the coated paper before and after compression Fig. 5 is an elevation of a builtupcontact bank; and Fig. 6 shows in detail a particularly suitable form of metal terminal strip.

. It has been found that terminal banks, built up in the usual way, of superimposed layers of plastic insulation coated paper,

sheets and metal terminal strips are liable to deteriorate and their, usefulness become seriously impaired after a time, due to the Specification of Letters Patent.

Patented Apr. d, 1916.

Application filed Jilly 6, 1914. Eloliai No. 849,344..

structure has been formed by the application of pressure suiiicient to give a umiorm spacing of the terminals and the proper overall dimensions: It is believed that this tendency is due to the cold flow? of the in sulating compoundcovering the paper. In other words, it is due to the ability of a compound plastic above ordinary temperatures but'practically solid at ordinary temperatures, to creep or slowly change its position at ordinary temperatures. The terminal bank of this invention is practically free from these objections, which makes it a highly satisfactory structure, particularly from the standpoint of maintenance.

The structure is composed of superimposed layers of insulation coated paper 5 and metal terminal strips 6. The insulation coating on the paper sheets is a composition which is, or may become, plastic at temperatures above ordinary temperatures, so that all the surplus may be readily s ueezed out from between the paper and meta strips and all'the fissures and crevices in the paper filled therewith. The paper without insulation is of a thickness considerably in excess of the distance between, the terminal strips'of the finished bank, and is of a com paratively spongy or porous nature, so that when the proper amount of pressu e is applied the terminals will be properly and uniformly spaced, andthe paper therebetween will be so compressed that its thickness plus the films of compound yet remaining will make upthe distance between adj acentterminal strips. This change in cross-section lsplainly shown in Figs. 2, 3 and 4. The

banks thus made'up may be individually held together and supported by clamping bars 10 and holding screws 11, or several may be piled up and collectively held by the clamping members 10 and 11.

A particularly suit/able form of metal terminal strip is shown in Fig. 6. This detail may be readily stamped by a punch press,

projections 15 serving as terminals tobe engaged by movable brushes or other contact members of the switchboard. The c0nnect-. ing wires may be readily attached by furnishing suitable lateral extensions 16. The terminal strips are provided with openings 17, through which holding or centering screws, such as 18, may pass. They also serve to reduce the body of metal, resulting in a lowering of the electrostatic capacity.

The invention claimed is:

l. A terminal bank comprising superimposed, compressed and substantially uniformly-spaced layers of insulation coated paper, and metal terminal strips, the distance between adjacent terminal strips after compression being less than the thickness of the paper, minus its coating, before eo1npression.

2. The process of i'ornung a tern'unal bank, which consists in superposing layers of insulation coated paper and metal termi- -nal strips, and compressing the bank thus CHARLES F. BALDXVIN.

Witnesses:

Ii. L. STAIIL, E. EnLnn. 

